Pushbutton buckle with slide action



Aug. 11,, 31970 R. w. STOFFEL PUSHBUTTON BUCKLE WITH SLIDE ACTION 3Sheets-Sheet 1 Filed April 15. 1968 INVENTOR. ROBERT W. STOFFEL FIG-3 BYATT Aug. 11, 1.970 R. w. STOFFEL 3,523,340

PUSHBUTTQN BUCKLE WITH SLIDE ACTION Filed April 15, 1968 5 Sheets-Sheet2 FIG-5 INVENTOR.

ROBERT w. STOFFEL BY 2/, 44 ,6, I ATT NEYS,

Aug.11,,1970 R. w. STOFFEL 2 PUSHBUTTON BUCKLE WITH SLIDE ACTION FiledApril 15, 1968 3 Sheets-Sheet 3 9 INVENITOR.

ROBERT w. STOFFEL F| Gr W ATTORNEYS United States Patent 01 ice3,523,34'0 Patented Aug. 11, 1970 US. Cl. 24-230 12 Claims ABSTRACT OFTHE DISCLOSURE A seat belt buckle in which the tongue overlaps the baseof the buckle housing in its locking position with locking means on thetongue being engageable with locking means in the base to prevent motionof the tongue parallel to the base. The locking means on the tongue andthe base are separable by motion of the tongue perpendicular to thebase. A spring-biased hold-down plate in the housing is slidably mountedbetween a hold-down position where it prevents motion of the tongueperpendicular to the base and a release position where it allows suchmotion. A pushbutton, supported for motion toward and away from the baseis connected by linkage means to the hold-down plate and adapted so thatdepression of the pushbutton moves the hold-down plate parallel to thebase to its release position from its hold-down position.

BACKGROUND OF THE INVENTION This invention relates to seat belt buckles,and more particularly to a pushbutton buckle and tongue assembly inwhich the pushbutton is supported for motion perpendicular to the baseof the buckle and connected by linkage means to a hold-down platesupported for motion parallel to the base between a first positionwherein it prevents separation of the tongue from its locking positionadjacent the base of the buckle, and a second position wherein itpermits the tongue to be separated from the base by a motionperpendicular to the base.

Pushbutton seat belt buckles have become increasingly popular becausethe pushbutton is not exposed to accidental forces which might tend torelease the buckle locking mechanism. Heretobefore pushbutton buckleshave generally been employed with a buckle locking mechanism in which apivotally mounted latch in the buckle housing engages an aperture in thetongue as the tongue is inserted through a suitable opening in thehousing. A spring biased lever disposed in the housing provides amotion-transmitting connection between the pushbutton and the latch toenable the user to pivot the latch to a tongue-release position bydepressing the pushbutton.

Another type of buckle locking mechanism is shown in the Pat. 3,127,655issued to A. G. Carter and may be characterized as a slide-actionlocking mechanism. In this form of mechanism, the tongue upon insertioninto the buckle housing engages a fixed abutment in the base whichprevents motion of the tongue parallel to the base as opposed to amovable latch member which engages the tongue in conventional buckles.In order to maintain engagement of the tongue with the base of thebuckle, a slidably mounted latch or hold-down plate is supported in thebuckle for motion parallel to the base between a first position in whichit overlaps the locking position of the tongue to prevent separation ofthe tongue from the base, and a second position in which it allowsseparation of the tongue from the base. This type of locking mechanismhas several advantages in that it provides for a very compact buckle andis very reliable in operation. The prior art, to my knowledge, does notdisclose a seat belt buckle in which a pushbutton release member isincorporated with a slide-action locking mechanism.

SUMMARY The broad purpose of the present invention is to provide a seatbelt buckle assembly having a pushbutton release member coupled with aslide-action locking mechanism to provide a buckle assembly which ismore compact than conventional pushbutton buckles and has thereliability and simplicity of a slide-action locking mechanism.

The preferred embodiment of the present invention em- I ploys a buckleassembly housing a slide-action lockingmechanism in which the hold-downplate is supported for motion in the buckle between its hold-down andits release position in directions parallel to the base. The pushbuttonis supported above the hold-down plate for a motion perpendicular to thebase and connected to the holddown plate by the combination of aparallelogram linkage and a pivotally mounted crank member. Theparallelogram linkage is mounted on the underside of the pushbutton suchthat depression of the pushbutton pivots the linkage so that it hascomponents of motion both parallel and perpendicular to the base. Thecrank member connects the parallelogram linkage to the hold-down plateand is supported so that motion of the linkage toward the base pivotsthe crank member with respect to the linkage so that it also has acomponent of motion parallel to the base. Thus the total distancetraveled by the hold-down plate in response to depression of thepushbutton is the sum of the components of motion parallel to the baseof the parallelogram linkage and the crank member. The combination ofthe linkage and the crank provides several advantages. The totaldepression required of the pushbutton in order to release the tongue isreduced so that the overall height of the buckle assembly is extremelythin as compared to conventional pushbutton buckles. Secondly,

only a very low release efiort need be applied to the pushbutton topermit uncoupling of the tongue from the buckle.

Another feature of the preferred buckle assembly is a novel adjustingpin for connecting the seat belt to the buckle housing. The adjustingpin has a novel shape that allows the user to easily adjust the lengthof the belt and then provides a non-yielding connection between thebuckle housing and the belt. The pin has a longitudinal groove with aconcave belt-clamping surface that cooperates with a convexbelt-clamping surface on the buckle to firmly connect the belt to thebuckle, but which easily separates from the belt to permit adjustment.

Another feature of the present invention lies in the construction of thehold-down plate and the buckle housing. The housing is preferably formedof a steel plate having a flat base and a pair of up-turned sides whichterminate in a pair of inwardly bent flanges to form a channel-likesection for receiving the tongue as well as for mounting the hold-downplate. The hold-down plate is mounted adjacent and below the flanges andhas a pair of round-headed rivets facing the lower surface of theflanges. The flanges are dimpled in such a manner that they form a pairof bulges facing the hold-down plate. As the hold-down plate movestoward its hold-down position the rivets on the hold-down plate engagethe bulges on the flanges so that the hold-down plate is cammed towardthe base of the buckle in such a manner that the hold-down plate and thelocking tongue are wedged between the base and the flanges. In additionto providing a better connection between the tongue and the buckle, thebulges on the flanges accommodate greater manufacturing tolerances andreduce the sliding friction of the hold-down plate.

3 Still other-advantages of the present invention will readily occur tothose skilled in the art to which the invention pertains upon referenceto the following detailed description.

DESCRIPTION OF THE DRAWINGS The description refers to the accompanyingdrawings in which like reference characters refer to like partsthroughout the several views in which:

FIG. 1 is a perspective view of the interior of a passenger compartmentof a motor vehicle showing an oecupant of the vehicle coupling himselfto a seat belt restraining system by a buckle assembly illustrating thepreferred embodiment of the invention;

FIG. 2 is an enlarged perspective view of the buckle assembly of FIG. 1;

FIG. 3 is a sectional view of the preferred buckle assembly showing thetongue disposed in its locking position in the buckle housing;

FIG. 4 is an exploded view of the preferred buckle assembly;

FIG. 5 is an enlarged view showing the motion of parallelogram linkageon the underside of the pushbutton;

FIG. 6 is an enlarged schematic view showing the crank member engagedwith the holddown member with the pushbutton in its raised position;

FIG. 7 is a view similar to FIG. 6, but showing the pushbutton depressedand the hold member in its release position;

FIG. 8 is an enlarged view showing the bulge on the underside of theflange of the buckle base and its relationship to the rivet head on thehold-down plate; and

FIG. 9 is a sectional view through a modified form of the buckleassembly without the retaining pin arrangement.

DESCRIPTION OF THE PREFERRED EMBODIMENT Now referring to the drawings,FIG. 1 shows an occupant 10 of a vehicle 12 on a seat assembly 14 in thepassenger compartment of the vehicle with a seat belt restraining system16. The restraining system 16 comprises a pair of belt sections 18- and20. The lower end of the belt section 18 is connected to the floor ofthe vehicle 12 by suitable means such as retractor 22, and the lower endof the belt section 20 is anchored to the floor by means (not shown).

The preferred buckle assembly 24 comprises a tongue member 26 carried onthe free end of the belt section 18 and a buckle means, generallyindicated at 28, carried on the free end of the belt section 20. Theoccupant 10 encloses himself in the restraining system 16 by joining thetongue 26 with the buckle means 28 which has an internally mountedlocking mechanism.

The tongue 26 is preferably formed of a plate-like section of metal witha leading edge 30 and a pair of tapered side edges 32 and 34 terminatingrearwardly in a pair of lateral shoulders 36 and 38. The tongue 26 has asemicircular locking aperture 39 which is centrally located rearwardlyof the leading edge 30.

The buckle means 28 comprises a metal base member 40 and a plastic covermember 42 mounted on the base member 40 to form a buckle-receivingopening 43. The base member 40 is formed of a plate-like section ofsteel into a flat base section 44 and a pair of upturned sides 46 and 48terminating at their upper edges in a pair of inwardly bent flanges 50and 52. Flanges 50 and 52 are spaced above and parallel to the basesection 44. The base section 44 has a pushed up abutment 54 which isengageable with the aperture 39 when the tongue 26 is disposed in itslocking position in face-to-face relationship with the base section 44.Thus it can be seen that the aperture 39 in the tongue and the abutment54 of the base member form cooperating locking means which, whenengaged, prevent the tongue 26 from being removed from the base number40 in a direction parallel to the base section 44. The aperture 39 andthe abutment 54 are engageable and separable by motion of the tongue 26in directions perpendicular to the base.

The base member 40 also has an upturned section 56 which forms a crushbar and extends above the flanges 50 and 52. The base member 40 also hasa reverse bent stiffener portion 58 which with the turned-up portion 56defines a transverse edge of an opening in the base 44 for receiving theseat belt section 20.

The cover member 42 is mounted on the base member 40 by suitable meanssuch as lugs 60 and 62 which snap under the flanges of the base member.The cover 42 also has an opening 64 in which is slidably disposed apushbutton 66. The pushbutton has a pair of lugs 68 (only one of whichis shown) which are disposed in a pair of sockets 70 in the cover memberwhich guide the pushbutton for motion in directions perpendicular to thebase section 44.

A guide plate 72 is mounted on the base section 44 of the base memberand has a contour 74 complementary to the profile of the contour of thetongue 26 so that it positions the tongue 26 in its locking position.The guide plate has substantially the same thickness as the tongue 26and is formed with a pair of downwardly depending lugs 76 which seat insuitable openings formed in the base 44 on opposite sides of theup-turned section 56 and a pair of shoulders 78 which are in abutmentwith the up-turned section 56. The mid-section 80 of the guide plate isspaced from the up-turned section 56 to provide a seat for a leaf spring8-2 which has its ends in abutment with the turned-up section 56 and abowed mid-section extending toward the mid-section 80 of the guideplate.

A hold-down plate 84 is slidably mounted on the guide plate 72 formotion parallel to the base 44 with its rear edge 86 in abutment withthe spring 82. The spring 82 biases the hold-down plate 84 toward theopening 43 so that it is normally disposed in a holddown positionwherein the mid-section 88 of its forward edge overlaps the leading edge30 of the tongue when the tongue is in its locking position. The forwardedge of the hold-down plate also has a pair of tapered side edges 90 and92 which do not overlap the tongue 26, and a pair of end edges 94 and 96which extend beyond the forward edge of the guide plate 72 and overlapthe shoulders 36 and 38 of the tongue.

Thus when the hold-down plate is in its hold-down position, it overlapsthe leading edge of the tongue and also a pair of points on the sideedges of the tongue which are separated by non-overlapped portions ofthe tongue. The tongue is engaged by the hold-down plate, at positionsboth forwardly and rearwardly of the engagement of the aperture 38 ofthe tongue with the abutment 54 of the base. This three point engagementis achieved by moving the hold-down plate in a very short stroke ofabout inch from its hold-down position to its release position.

The hold-down plate 84 also has a pair of apertures 98 adjacent its rearedge which receive downwardly depending legs of a staple 100 whichengage the rear edge of the guide plate 72 to limit the travel of theholddown plate toward the opening 43. A pair of rivets 102 are mountedadjacent the side edges of the hold-down plate 84 beneath the flanges 50and 52 of the base member. When the buckle mechanism is being assembled,the holddown plate is inserted within the base member and then therivets are inserted through a pair of openings 104 in the flanges andthreadably mounted in place between a pair of dimpled sections 106 inthe flanges.

Referring to FIG. 8, the hold-down plate 84 is shown in its releaseposition. As the hold-down plate moves toward its hold-down position itapproaches a bulge 108 formed on the lower side of the flange 52 by thedimpled section 106. As the rivet 102 engages the bulge 108, thehold-down plate 84 is cammed toward the base section 44 so that it andthe tongue 26 are firmly held in position between the flange 52 and thebase section 44. It is to be understood of course that a similar bulge108 is formed below each of the dimpled sections 106. The curvilinearstructure provided by the head of the rivet 102 could be formed by othermethods. This structure allows greater manufacturing tolerances andeasier assembly as well as eliminating the sliding friction that existsin conventional structure between the hold-down plate 84 and the flangesof the base member 40.

The downward motion of the pushbutton 42 is transmitted to the hold-downmember 84 by a parallelogram linkage generally indicated at 110 and acrank member 112. The linkage 110 comprises a pair of similarly-shapedlinks 114 and 116 each having their ends pivotally mounted on the cover42 for rotation about an axis parallel to the base 44. The two links 114and 16 have eccentric portions 118 and 120 respectively connected by aplate-like connecting link 122 which is slidably engaged with the lowersurface of the pushbutton as can best be seen in FIG. 3.

As best seen in FIG. 5, depression of the pushbutton 66 toward the basecauses the eccentric portions 118 and 120 of the links to pivot abouttheir ends so that they have a first component of motion perpendicularto the base and a second component of motion parallel to the base in adirection away from the opening 43. The crank member 122 has its upperend connected to the eccentric portion 120 of the link 116 and its lowerend engaged in a recess 124 of the hold-down plate. Thus it can be seenthat the upper end of the crank 112 moves with the eccentric portion 120of the link.

As can best be seen in FIGS. 6 and 7, the downward motion of theeccentric portion 120 of the link 116 toward the base causes the crank112 to pivot in such a manner that its lower end has a component ofmotion parallel to the base 44. Thus it can be seen that thedisplacement of the hold-down plate from its hold-down position,illustrated in FIG. 6 wherein it overlaps the tongue 26, to its releaseposition is the sum of the component of motion of the eccentric 120parallel to the base with respect to the pushbutton '66, and thecomponent of motion of the lower end of the crank 112 parallel to thebase with respect to the eccentric 120. When the depressive force on thepushbutton is released, the spring 82 biases the hold-down plate 84forwardly toward its normal hold-down position illustrated in FIG. 6. Asbest seen in FIG. 3, a spring 126 mounted on eccentric 120 acts betweenthe connecting link 122 to bias the crank 112 away from the connectinglink to maintain its seated position is the recess 124 in the holddownplate.

It is to be noted that the forward edge of the holddown plate has acammed portion 128 which engages the leading edge 30 of the tongue whenthe tongue is inserted in the buckle housing and cams the tonguedownwardly until such time as the locking aperture 39 in the tongueengages the abutment 54 so that the tongue snaps into its lockingposition in face-to-face relationship with the base 44.

Now referring to FIG. 3, the belt 20 is preferably looped around aretaining pin 130 which is disposed behind the up-turned section 56 andhas a generally tear drop cross-section with a concave belt-clampinggroove 132. The concave groove 132 extends the full length of themid-section of the pin 130 and faces the reversely bent transverse edge58 which presents a convex beltclamping surface to the pin. By applyinga force ,on the belt 20 which moves the pin 130 toward the transverseedge 58, the belt becomes clamped between the convex portion formed bythe reversely bent section 58 and the concave section 132. Changing thedirection of the force on the belt to move the pin 130 away from theedge 58 releases the belt for adjustment. A pair of lateral ear portions134 formed on the ends of the pin 130 are disposed between the flanges50 and 52 and base' 44 of the base member. A staple 136 which isinserted through the rear end of the base member has a pair of elongatedlegs 138 and 140 on which the ears 134 of the retaining pin ride. Thusthe pin is movable toward and away fnom the reversely bent portion 58parallel to the base and retained against rotation about itslongitudinal axis. The tips of the legs 138 and 140 have cutout portions142 which engage the rear edge of the guide plate adjacent the feet 76.

FIG. 9 shows a modified form of a buckle which has the same internallocking mechanism as the preferred embodiment but with a shortened basemember 44 and an aperture 138 through which the belt 20 is loopedwithout a retaining pin. This modified form of the invention shows howthe buckle mechanism can be further reduced in size as compared toconventional buckle mechanisms with the seat belt adjustment beingaccomplished by means removed from the buckle mechanism. The embodimentof FIG. 9 also has a shortened cover member 140 to accommodate themodified base member.

Thus it is to be understood that I have described in detail an improvedseat belt buckle assembly which incorporates the advantages of both thepushbutton release means as well as the slide action locking mechanism.This is possible by employing a novel form of linkage means whichconnect the pushbutton 66 with the hold-down plate 84 in such a mannerthat depression of the pushbutton toward the base moves the holddownplate parallel to the base.

Although I have described but two embodiments of my invention, it is tobe understood that various changes and revisions can be made thereinwithout departing from the spirit of the invention.

What is claimed is:

1. A pushbutton seat belt buckle assembly, comprising:

(a) a tongue having a first locking section;

(b) buckle housing means having an opening for receiving said tongue ina locking position and a planar base with a second locking section, thelocking section on the tongue being engageable with the locking sectionon the base to lock the tongue against motion in a direction parallel tothe base, and being separable from the locking section on the base bymotion in a directional normal to the base;

(c) a hold-down member disposed in the buckle housing means for motionin directions parallel to the base between a hold-down position and arelease position, said hold-down member having a portion which isoperative when the hold-down member is in its hold-down position tomaintain engagement of said first and second locking sections, saidportion being inoperative to prevent separation of said first and secondlocking sections when the hold-down member is in its release position;

(d) bias means urging the hold-down member toward its hold-downposition;

(e) a pushbutton mounted on said buckle housing means for motion towardand away from the base; and

(f) means connecting said pushbutton with said holddown member so thatmotion of the pushbutton toward the base moves the hold-down memberparallel to the base from its hold-down position to its releaseposition.

2. A seat belt buckle assembly as defined in claim 1, wherein saidtongue is formed with a socket, and the base has an abutment engageablewith the socket extending normal to the surface of the base.

3. A seat belt buckle assembly as defined in claim 1, wherein said meansconnecting said pushbutton with said holddown member comprises a leverpivotally supported on said housing means for motion about an axisparallel to the base, said lever having an eccentric portion spaced fromsaid axis and engageable with the pushbutton in such a manner thatmotion of the pushbutton toward the base pivots the lever so that theeccentric portion has a component of motion parallel to the base, andmeans connecting the eccentric portion to the holddown member totransmit the parallel component of motion to the holddown member.

4. A seat belt buckle assembly as defined in claim 1, wherein said meansconnecting said pushbutton with said hold-down member comprises a crankmember supported between the pushbutton and the hold-down member andhaving one end connected to the pushbutton and its other end connectedwith the hold-down member in such a manner as to move the hold-downmember parallel to the base as the pushbutton is depressed toward thebase.

5. A seat belt buckle assembly as defined in claim 1, wherein said meansconnecting said pushbutton with said hold-down member comprise a leverpivotally supported on said housing means for motion about an axisparallel to the base, said lever having an eccentric portion separatedfrom said axis and connected with the pushbutton in such a manner thatmotion of the pushbutton toward the base pivots the lever so that theeccentric portion has components of motion parallel to and normal to thebase, and a crank member having a first end connected to the eccentricportion of the lever and its second opposite end connected with thehold-down member so that motion of the eccentric portion toward the basemoves the second end of the crank in a direction parallel to the basewith respect to its first end whereby the distance the hold-down membermoves parallel to the base as the pushbutton is depressed toward thebase is the sum of the parallel components of movement of the eccentricportion with respect to the pushbutton, and the second end of the crankwith respect to the eccentric portion.

6. A seat belt buckle assembly as defined in claim 1, wherein said meansconnecting said pushbutton with said hold-down member comprises a pairof similarly formed levers pivotally supported on said housing means formotion about a pair of individual spaced axes, each of said axes beingdisposed parallel to the base and to one another, each of said levershaving an eccentric portion separated from its axis of motion; aconnecting link connecting the eccentric portions of said levers to forma parallelogram linkage, said connecting link being engageable with saidpushbutton as the pushbutton is depressed toward the base in such amanner as to have a component of motion parallel to the base; and acrank member having a first end movable with said connecting link andits second, opposite end in abutment with the hold-down member so thatmotion of the connecting link toward the base moves the second end ofthe crank member parallel to the base, with respect to its first endwhereby the distance the hold-down member moves parallel to the base asthe pushbutton is depressed toward the base is the sum of the componentsof movement parallel to the base of the connecting link with respect tothe pushbutton, and the second end of the crank with respect to theconnecting link.

7. A seat belt buckle assembly as defined in claim 1, wherein the tongueis formed of a plate-like section with a portion of its perimeter formedwith a predetermined contour, and including a guide plate in saidhousing means having a contour complementary with respect to theperimeter of the tongue engageable with the tongue to position thetongue in its locking position.

8. A seat belt buckle assembly as defined in claim 1, wherein said basehas a locking abutment; said tongue is formed of a plate-like sectionhaving a locking aperture engageable with the butment in the base, saidhold-down member has first edge portions for overlapping the leadingedge of the tongue in its locking position and other edge portions foroverlapping the side edges of the tongue at points between theengagement of said locking aperture with said abutment and the trailingedge of said tongue, said first edge portions and said other edgeportions of the hold-down member being separated by edge portions thatdo not overlap said tongue.

'9. A seat belt buckle assembly as defined in claim 1, wherein saidhousing means includes a housing having a flange fixed with respect tothe base and spaced therefrom with a curvilinear structure facing saidbase, and said hold-down member and said tongue are formed of a pair ofplate-like sections movable between said base and said flange, said holddown member having a second curvilinear structure engageable with thecurvilinear structure on the flange as the hold-down member approachesits hold-down position to wedge the hold-down member and the tonguebetween the flange and the base.

10. A seat buckle assembly as defined in claim 8, wherein at least oneof said curvilinear structures is a bulge.

11. A seat belt buckle assembly as defined in claim 1, wherein saidtongue engages the hold-down member as it is inserted into the housingto move the hold-down member toward its release position.

12. A pushbutton seat belt buckle assembly, comprismg:

(a) a plate-like tongue having first locking means;

(b) a buckle housing having a planar base fixed structure overlappingthe base, and an opening for receiving the tongue to a locking positionin face-to-face relationship with the base, said base having secondlocking means engageable with the looking means in the tongue to preventmotion of the tongue parallel to the base from its locking position, thelocking means on the tongue being separable from the look ing means onthe base by motion of the tongue perpendicular to the base;

(0) a hold-down plate disposed in said housing between said fixedstructure and the base, said hold-down plate being movable in directionsparallel to the base toward and away from a hold-down position andhaving portions overlapping the locking position of said tongue in itshold-down position to maintain engagement of the locking means in thetongue and the base;

(d) means biasing the hold-down plate toward its holddown position;

(e) first curvilinear structure on the fixed structure of said housingfacing said base;

(f) second curvilinear structure on the hold-down plate engageable withthe first curvilinear as the holddown plate approaches its hold-downposition so as to wedge the hold-down plate and the tongue between thebase and the fixed structure of the housing; and

(g) release means for moving the hold-down plate away from its hold-downposition to permit separation of the tongue from the base.

References Cited UNITED STATES PATENTS 9/ 1961 Warner 4/ 1964 Carter. 9/1966 Hamann 24-196 5/1967 Van Noord 24-196 X 9/1967 Straight 24-77 11/1968 Hemphill.

BERNARD A. GELAK, Primary Examiner

